Quick theory question about 5/10 rule

[Vinny80]

Ok, we all know the 5/10 rule from pot-limit/no-limit poker by Ciafonne and the other dude. I've got a question about it.

Let's say I'm playing 2-5 NL and both villain and I are in for 100BB. It's folded to me on cutoff and I'm making it 20$ with pocket 4. Small blind, your typical regular tag, makes it 65$ then back to me heads up.

My question is what numbers am I looking at to evaluate the 5/10 rule. Do I take the amount villain raises (45$) since I already have 20$ commited or the whole bet (65$).

And when I'm considering stack sizes, am I using the starting stack (500$) or what's left in villain stack (435$).

It may seem as a useless question, but it makes the decision (as a theory point of view) go one way or another depending on the numbers picked to evaluate it.

Thanks!